U.S. patent number 7,074,444 [Application Number 10/300,197] was granted by the patent office on 2006-07-11 for method for producing a dehydrated whole food product.
Invention is credited to Geoffrey Margolis.
United States Patent |
7,074,444 |
Margolis |
July 11, 2006 |
Method for producing a dehydrated whole food product
Abstract
A method of preparing a reconstitutable, dehydrated whole bean
product is shown. The method calls for utilizing a combination
convection/microwave heating chamber to dry cooked whole beans in
such a way as to preserve the integrity of the beans and, thus,
significantly enhance the texture and quality of the bean product.
The method requires a shorter amount of time than, and enables a
significant reduction in the amount of bird mouthing that, is
prevalent in existing methods.
Inventors: |
Margolis; Geoffrey (Los
Angeles, CA) |
Family
ID: |
32716815 |
Appl.
No.: |
10/300,197 |
Filed: |
November 19, 2002 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20030068417 A1 |
Apr 10, 2003 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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09640297 |
Aug 16, 2000 |
6482457 |
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Current U.S.
Class: |
426/242; 426/459;
426/464; 426/502; 426/503; 426/506; 426/507; 426/508; 426/516;
426/518; 426/634 |
Current CPC
Class: |
A23L
5/13 (20160801); A23L 11/05 (20160801); A23L
11/07 (20160801) |
Current International
Class: |
A23L
1/20 (20060101); A21D 8/00 (20060101); A23L
1/212 (20060101); A23P 1/00 (20060101) |
Field of
Search: |
;426/459,634,516,518,502,503,506,464,507,508 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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562648 |
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Jul 1944 |
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GB |
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648373 |
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Jan 1951 |
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GB |
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783974 |
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Oct 1957 |
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GB |
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938381 |
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Oct 1963 |
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GB |
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1017519 |
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Jan 1966 |
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GB |
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2118421 |
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Nov 1983 |
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GB |
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2163938 |
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Mar 1986 |
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GB |
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Other References
Robert Noyes, "Dehydration Processes for Convenience Foods", 1969,
Noyes Development Corporation, p. 237. cited by other .
M.R. Molina, et al. , "Heat Treatment: A Process to Control the
Development of the Hard-to-Cook Phenomenon in Black Beans
(Phaseolus vulgaris)," 1976, Journal of Food Science, vol. 41, pp.
661-666. cited by other .
H.J. Morris, et al., "Processing Quality of Varieties and Strains
of Dry Beans," Jun. 1950, Food Technology, pp. 247-251. cited by
other .
Derwent Abstract--Acc. No. 1996-127368 for Ru 2038797 published
Jul. 9, 1995. Inventors: Doenko et al. cited by other.
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Primary Examiner: Weier; Anthony
Attorney, Agent or Firm: Pillsbury Winthrop Shaw Pittman
LLP
Parent Case Text
RELATED APPLICATION DATA
This is a continuation-in-part of Ser. No. 09/640,297, filed Aug.
16, 2000, now U.S. Pat. No. 6,482,457.
Claims
What is claimed is:
1. A method for producing a reconstitutable dehydrated chunky bean
product, comprising: a. hydrating raw beans; b. cooking the
hydrated beans; c. dividing the cooked beans into a first unchopped
portion and a second unchopped portion; d. chopping said first
portion of the cooked beans to form a composition of a desired
texture; e. forming the texturized composition into a generally
flat sheet; f. drying the flat sheet of texturized composition; g.
forming the sheet into chunks; h. drying said second unchopped
portion using a combination microwave-convection heating process;
and i. adding the dried second unchopped portion of beans to said
chunks.
2. The method of claim 1, wherein said generally flat sheet of
texturized composition has a ribbed top surface.
3. The method of claim 2, wherein said generally flat sheet of
texturized composition has a ribbed bottom surface.
4. A method for producing a reconstitutable dehydrated chunky bean
product, comprising: a. hydrating raw beans; b. cooking the
hydrated beans; c. dividing the cooked beans into a first unchopped
portion and a second unchopped portion; d. chopping said first
portion of the cooked beans to form a composition of a desired
texture; e. forming the texturized composition into a generally
flat sheet; f. drying the flat sheet of texturized composition; g.
forming the sheet into chunks; h. arranging the second unchopped
portion of cooked beans into multiple bean layers; i. drying said
layers of cooked beans using microwave energy; and j. adding the
dried second unchopped portion of beans to said chunks.
5. The method of claim 4, wherein, in step (h), the second
unchopped portion of cooked beans is arranged into at least four
layers.
6. The method of claim 4, wherein, in step (i), the layers of
cooked beans are dried using convective heating in addition to said
microwave energy.
7. The method of claim 6, wherein the layers of cooked beans are
dried by simultaneous exposure to said microwave energy and
convective heating.
8. The method of claim 4, wherein the generally flat sheet of
texturized composition has a top surface and a bottom surface and
at least one of said top and bottom surfaces is ribbed.
9. A method for producing a reconstitutable dehydrated chunky bean
product, comprising: a. hydrating raw beans; b. cooking the
hydrated beans; c. dividing the cooked beans into a first unchopped
portion and a second unchopped portion; d. chopping said first
portion of the cooked beans to form a composition of a desired
texture; e. forming the texturized composition into a generally
flat sheet; f. drying said second unchopped portion using a
combination microwave-convection heating process; g. adding the
dried second unchopped portion of beans to said sheet; h. drying
the flat sheet of texturized composition; and i. forming the sheet
into chunks.
10. The method of claim 9, wherein the generally flat sheet of
texturized composition has a top surface and a bottom surface and
at least one of said top and bottom surfaces is ribbed.
11. A method for producing a reconstitutable dehydrated chunky bean
product, comprising: a. hydrating raw beans; b. cooking the
hydrated beans; c. dividing the cooked beans into a first unchopped
portion and a second unchopped portion; d. chopping said first
portion of the cooked beans to form a composition of a desired
texture; e. forming the texturized composition into a generally
flat sheet; f. arranging the second unchopped portion of cooked
beans into multiple bean layers; g. drying said layers of cooked
beans using microwave energy; h. adding the dried second unchopped
portion of beans to said sheet; i. drying the flat sheet of
texturized composition; j. forming the sheet into chunks.
12. The method of claim 11, wherein, in step (g), the layers of
cooked beans are dried using convective heating in addition to said
microwave energy.
13. The method of claim 12, wherein the layers of cooked beans are
dried by simultaneous exposure to said microwave energy and
convective heating.
14. The method of claim 11, wherein the generally flat sheet of
texturized composition has a top surface and a bottom surface and
at least one of said top and bottom surfaces is ribbed.
15. A method for producing a reconstitutable dehydrated chunky bean
product, comprising: a. separately hydrating a first portion and a
second portion of unchopped raw beans to obtain respective first
and second portions of unchopped hydrated beans; b. separately
cooking each of said first and second portions of hydrated beans to
obtain respective first and second portions of unchopped cooked
beans; c. chopping said first portion of the cooked beans to form a
composition of a desired texture; d. forming the texturized
composition into a generally flat sheet; e. drying the flat sheet
of texturizedcomposition; f. forming the sheet into chunks; g.
drying the second portion of unchopped cooked beans by simultaneous
exposure to microwave energy and convective heating; and h. adding
the dried second portion of unchopped cooked beans to said
chunks.
16. The method of claim 15, wherein the generally flat sheet of
texturized composition has a top surface and a bottom surface and
at least one of said top and bottom surfaces is ribbed.
17. The method of claim 15, wherein, in steps (a) and (b), said
first portion of unchopped beans is hydrated and cooked under a
first set of processing conditions and said second portion of
unchopped beans is hydrated and cooked under a second set of
processing conditions.
18. The method of claim 17, wherein said first set of processing
conditions is the same as said second set of processing
conditions.
19. A method for producing a reconstitutable dehydrated chunky bean
product, comprising: a. separately hydrating a first portion and a
second portion of unchopped raw beans to obtain respective first
and second portions of unchopped hydrated beans; b. separately
cooking each of said first and second portions of hydrated beans to
obtain respective first and second portions of unchopped cooked
beans; c. chopping said first portion of the cooked beans to form a
composition of a desired texture; d. forming the texturized
composition into a generally flat sheet; e. drying the flat sheet
of texturized composition; f. forming the sheet into chunks; g.
arranging the second portion of unchopped cooked beans into
multiple bean layers; h. drying said layers of unchopped cooked
beans using microwave energy; and i. adding the dried second
portion of unchopped cooked beans to said chunks.
20. The method of claim 19, further including adding flavor
ingredients to each of said first and second portions.
21. The method of claim 19, further including adding oil to each of
said first and second portions.
22. The method of claim 19, further including adding a colorant to
each of said first and second portions.
23. The method of claim 19, wherein, in step (h), the layers of
unchopped cooked beans are dried using convective heating in
addition to said microwave energy.
24. The method of claim 23, wherein the layers of unchopped cooked
beans are dried by simultaneous exposure to said microwave energy
and convective heating.
25. The method of claim 19, wherein the generally flat sheet of
texturized composition has a top surface and a bottom surface and
at least one of said top and bottom surfaces is ribbed.
26. The method of claim 19, wherein, in steps (a) and (b), said
first portion of unchopped beans is hydrated and cooked under a
first set of processing conditions and said second portion of
unchopped beans is hydrated and cooked under a second set of
processing conditions.
27. The method of claim 26, wherein said first set of processing
conditions is the same as said second set of processing
conditions.
28. A method for producing a reconstitutable dehydrated chunky bean
product, comprising: a. separately hydrating a first portion and a
second portion of unchopped raw beans to obtain respective first
and second portions of unchopped hydrated beans; b. separately
cooking each of said first and second portions of hydrated beans to
obtain respective first and second portions of unchopped cooked
beans; c. chopping said first portion of the cooked beans to form a
composition of a desired texture; d. forming the texturized
composition into a generally flat sheet having ribbed top and
bottom surfaces; e. drying the ribbed sheet of texturized
composition; f. forming the sheet into chunks; g. drying the second
portion of unchopped cooked beans using convective heating; and h.
adding the dried second portion of unchopped cooked beans to said
chunks.
29. The method of claim 28, further including, prior to step (g),
arranging the second portion of unchopped cooked beans into
multiple bean layers and, in step (g), drying said layers using
convective heating.
30. The method of claim 28, further including adding to at least
one of said first and second portions a member selected from the
group consisting of flavor ingredients, oil, and colorant.
31. The method of claim 1, wherein, in step (b), the hydrated beans
are cooked in a stationary vessel.
32. The method of claim 31, wherein, in step (a), the raw beans are
hydrated in said stationary vessel.
33. The method of claim 4, wherein, in step (b), the hydrated beans
are cooked in a stationary vessel.
34. The method of claim 33, wherein, in step (a), the raw beans are
hydrated in said stationary vessel.
35. The method of claim 9, wherein, in step (b), the hydrated beans
are cooked in a stationary vessel.
36. The method of claim 35, wherein, in step (a), the raw beans are
hydrated in said stationary vessel.
37. The method of claim 11, wherein, in step (b), the hydrated
beans are cooked in a stationary vessel.
38. The method of claim 37, wherein, in step (a), the raw beans are
hydrated in said stationary vessel.
39. The method of claim 15, wherein, in step (b), at least one of
said first and second portions of unchopped hydrated beans is
cooked in a stationary vessel.
40. The method of claim 17, wherein at least one of said first and
second portions of unchopped beans is cooked in a stationary
vessel.
41. The method of claim 19, wherein, in step (b), at least one of
said first and second portions of unchopped hydrated beans is
cooked in a stationary vessel.
42. The method of claim 26, wherein at least one of said first and
second portions of unchopped beans is cooked in a stationary
vessel.
43. The method of claim 28, wherein, in step (b), at least one of
said first and second portions of unchopped hydrated beans is
cooked in a stationary vessel.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention is in the field of food products and, more
particularly, directed to a method for producing a dehydrated food
product, including whole cooked bean (and other such similar)
products in such a way as to preserve the structural integrity of
the bean which, in turn, helps provide a food product having
significantly enhanced texture and quality.
2. Background
The prevalence of fast-food style establishments in recent years
has been accompanied by an increased demand for reconstitutable
food products, such as, for example, dehydrated refried beans. From
an economic point of view, such products have several advantages.
For example, each establishment can buy and store the product in
bulk quantities without the risk of spoilage. Also, since the
product is normally reconstituted in a matter of minutes by adding
only water, there are savings in time, energy, and labor associated
with the use of these products. Finally, since there is no need to
continually prepare the food product in the conventional manner
(i.e., to make the food fresh, and on a daily basis), there is also
no need for each establishment to keep extra equipment (e.g.,
cookware, etc.) on the premises. As such, methods have been devised
to produce reconstitutable food products that, ideally, could be
prepared very quickly, and would have the taste, texture, and
appearance of their conventionally-prepared counterparts.
Current methods and apparati for producing such food products and,
more specifically, refried bean products, require that one consider
various factors. For example, to satisfy the requirement that the
raw beans be mixed as they are hydrated and, also, as they are
cooked, a number of the methods presently known employ rotating
vessels. Vessels that rotate are used so that the beans can be
contacted with a small amount of water that is diminishing as the
water is absorbed by the beans. Controlled amounts of water are
used during the cooking process in hopes that at the end, little or
no water remains--only the cooked, hydrated beans. This is
difficult to achieve, and the art has searched for various methods,
as excess water can result in yield loss (some of the beans will
dissolve into the water) and/or a pasty product that is difficult
to further process and dry. Merely placing the beans in water has
other shortcomings. For example, such a method can result in some
beans becoming too soft, while others do not become properly
hydrated. Further, prior art vessels are generally quite bulky,
which not only translates into added and more-frequent maintenance
requirements, but also makes it more difficult to achieve economies
of scale. Further still, generally, in many prior art vessels only
a small amount of beans can be treated. In other words, to achieve
the benefit of a small water-to-bean ratio, rotating vessels of
particular configurations and having limited capacities were used.
Even then, it is difficult to control the water absorption into the
beans.
Yet other shortcomings relate to the starting materials that are
used. In a typical prior art process for preparing refried beans,
dry, raw beans are placed into the vessel, and a small quantity of
water is added. Unless the vessel rotates, the beans on the top of
the pile could absorb a different amount of water as compared to
the beans at a position lower down. Further, as the water level in
the vessel decreases, yet further non-uniform water absorption
throughout the beans could result. It is known that raw beans
typically have an initial moisture content in the range 6% 14%.
However, current methods have difficulty using a batch of raw
material that spans this entire range because the disparity in
initial moisture levels exacerbates the variations in water
absorption during hydration with small amounts of water, which
would, in turn, result in a non-uniform final product. As such, in
order to use many prior art methods and apparatuses, the
practitioner is limited to using rotating vessels and to batches of
raw materials, each of which falls within a small sub-group of
initial moisture-content ranges (e.g., those in the 6 8% range, or
those in the 10 12% range, etc.).
In the current state of the art, there are also disadvantages
associated with the end product itself (e.g., with the dehydrated
bean product). For example, even though one goal of dehydrated food
products is to allow for rapid water take-up at reconstitution,
this goal is only partially met in current dehydrated bean
products. As is known in the art, most current methods produce
products that are either in the shape of small pellets or in the
shape of flakes or in the shape of fine powder. In the case of
pellets, because of the way in which the final product is prepared,
typically only a small portion of the surface area of each pellet
(i.e., typically, the two ends of each pellet) provides areas
through which water can easily be absorbed; the remainder of the
pellet's outer surface is inefficient in absorbing water. Flakes,
on the other hand, due to their method of manufacture, have a
harder outer surface and are generally treated with oil on their
surface, which is a water repellent, so that water take-up upon
reconstitution is actually slower than it may be otherwise.
Therefore, in both cases, water absorption rates are not
optimal.
Moreover, upon reconstitution, many of the dehydrated products
currently available turn into paste-like, or other similar, uniform
compositions, where there is generally a lack of texture in the
food. This is especially true with methods and apparatuses that
produce a granular, rather than a pelletized, or flake-like,
dehydrated product. In addition, regardless of the actual shape and
form of the final product, there is no simple provision in existing
methods and apparatuses for varying (i.e., custom making) the
texture of the final product as desired.
Reference is made to U.S. Pat. Nos. 4,676,990, 4,735,816, and
4,871,567 as further examples of the prior art. These references
illustrate various bean-making processes, but all have a number of
shortcomings. For example, in the '990 patent, a pelletized product
is produced by particularized processing steps and related
apparatus. In the '816 and '567 patents, a thin, flake-like product
is produced by means of yet other particularized processing steps
and apparatus. These processes are complicated and the final
products are only marginally close to refried beans made to have a
pleasant texture with a desired amount of bean particulates.
To address some of the issues relating to the lack of adequate
texture in the reconstituted food, attempts have been made in the
prior art to add dehydrated whole beans to the aforementioned
products. However, such attempts have been met with difficulties as
dehydration of cooked whole beans has generally been accompanied by
a considerable amount of "bird mouthing".
Bird mouthing, also referred to as "butterflying", is a phenomenon
wherein the whole bean splits along its two halves and opens during
the dehydration process. It is believed that bird mouthing is
caused by a differential rate of drying between the bean skin and
cotyledon, such that, during the dehydration process, the bean skin
dries more rapidly than the cotyledon, and thus, contracts (a
condition which is referred to as "case hardening"). As dehydration
continues, the slower-drying cotyledon develops internal vapor
pressure to an extent where the pressure ruptures the skin and
causes bird mouthing.
Reference is made to U.S. Pat. Nos. 3,290,159 and 4,871,567 as
examples of the prior art's attempts to reduce the amount of bird
mouthing in dehydration of whole beans. For example, the '159
patent discloses a two-stage dehydration process, wherein the first
stage involves a slower moisture-removal process, and the second
stage involves a more rapid dehydration process. Both stages of the
disclosed methodology are directed to drying using conventional air
dryers. Similarly, the '567 patent discloses a dehydration process
comprising two or more "stages". However, in contrast to the '159
patent, the '567 patent teaches a method involving incremental
decreases, rather than increases, in the amount of heat supplied
during the dehydration process. Nevertheless, neither methodology
seems to have resolved, to an appreciable degree, the problem of
bird mouthing.
An additional drawback associated with the process disclosed in the
'159 patent is that, in order to be effective, the process calls
for slow drying rates. Such slow drying rates translate into
relatively long drying times (e.g., on the order of 4 6 hours)
which, in turn, result in low levels of throughput per unit time.
Similarly, the process disclosed in the '567 patent calls for an
initial period of high-humidity drying which, again, results in
longer drying times. This is especially true when convective
heating is utilized to dry the beans since convective dehydration
efficiency drops off drastically during the latter stages of drying
particulate material when moisture diffusion from the center of the
particle controls the drying rate.
Food manufacturers have also used equipment and/or forms of energy
other than conventional air dryers to produce dehydrated food
products. In this regard, reference is made to U.S. Pat. Nos.
4,073,952 and 6,197,358. The '952 patent discloses a method of
making dehydrated potatoes, wherein the method includes drying
pieces of potato by exposing them simultaneously to microwave
energy and to hot air. The hot air is enriched with moisture to
maintain an average humidity of at least 83% in the oven during
most of the drying period. In addition, about 10 50% of the energy
used for drying is provided by moisture-enriched air that is heated
to between 75 and 255.degree. F. and, typically, to 100 150.degree.
F.
However, being unrelated to the production of dehydrated bean
products, the '952 patent does not address bird mouthing at all.
Rather, it teaches a combination microwave/hot air drying process
in order to minimize discoloration and loss of flavor for potato
pieces. Similarly, the '358 patent is related to a process in which
microwave energy may be used during the production of dehydrated
potato products, but not during the drying step.
The features and advantages of the present invention will become
more apparent through the following description. It should be
understood, however, that the detailed description and specific
examples, while indicating particular embodiments of the invention,
are given by way of illustration only and various modifications may
naturally be performed without deviating from the spirit of the
present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an illustration of a vessel and rotating member of an
apparatus that may be used in the practice of an embodiment of the
invention.
FIG. 2 shows a cross-sectional view of the vessel and rotating
member of FIG. 1, taken along line II--II.
FIG. 3 shows an illustration of a shaft and rotating member of an
embodiment of the vessel.
FIG. 4 shows an illustration of a channel and forming conduit of an
apparatus that may be used in the practice of an embodiment of the
invention.
FIG. 5 shows a cross-sectional view of the channel and forming
conduit of FIG. 4, taken along line V--V.
FIG. 6 shows a condensed flow-chart format of an embodiment of the
invention.
FIG. 7 shows a condensed flow-chart format of an alternative
embodiment of the invention.
FIG. 8 shows a condensed flow-chart format of an additional
embodiment of the invention.
FIGS. 9A 9C show various cross-sections of a sheet of textured
material according to an embodiment of the invention.
DETAILED DESCRIPTION
An embodiment of the present invention is related to a method or
process for producing a reconstitutable, dehydrated food product,
which may be practiced by use of apparatus comprising a stationary
hydration/cooking vessel, a chopping system, and a forming
mechanism. The hydration/cooking vessel is equipped with a
perforated internal baffle which rotates continuously to ensure
contacting of all beans or other foods with a small and continuous
diminishing quantity of water; the baffle holes ensure that fluids
within the vessel are exchanged freely between the two chambers of
the vessel as defined by the baffle. Once cooked, the beans are
transferred to the chopping system, wherein they are urged through
a channel, comprising a rotating blade that chops, and a perforated
plate that re-sizes, the beans into a texturized composition. The
blade speed and the size of the holes in the perforated plate can
be changed in order to achieve different textures within the
composition. The latter is then treated in a forming mechanism,
comprising a shaped conduit, wherein the composition is formed into
a generally flat sheet, which is then treated so as to produce an
improved reconstitutable dehydrated bean product. In certain
embodiments, the generally flat sheet may be ribbed, or ridged, on
either, or both, of its top and bottom surfaces.
The stationary hydration/cooling vessel of the present invention
has significant processing advantages. First, since the vessel is
stationary, it is relatively simple to construct large units which
result in substantial economies of scale. Second, by using a
horizontal cooking vessel with a perforated internal baffle having
a length and width that are substantially the same as the vessel,
it is easy to assure that, during processing, all of the beans are
gently and continuously contacted with a small, and diminishing
quantity of liquid.
Embodiments of the present invention are directed to a method of
preparing a reconstitutable, dehydrated food product by means of
hydrating and cooking raw beans, so that all of the cooked beans
achieve a similar moisture content, chopping the cooked beans and
forming the chopped beans into a flat sheet of texturized
composition, drying the sheet, and breaking the sheet into smaller
pieces.
The above-described process, particularly the sequence involving
the latter three steps, results in a dehydrated bean product that
absorbs water faster and more uniformly upon reconstitution. Also,
after the raw beans have been hydrated, excess liquid can be, if
desired, removed from the vessel, thus eliminating some flatulent
sugars from, and improving the digestibility of, the final bean
product. Moreover, salt, colorant, and other flavoring may be added
to a portion of the removed excess water and then added back to the
vessel before the beans are cooked. Alternatively, salt, colorant,
flavoring, and oil may be added during the chopping, or other
steps, of the above-described process. Finally, depending on the
desired texture and chunkiness of the final product, a portion of
cooked whole beans may be removed before the chopping step, and
then added to the beans in a subsequent step, or after drying to
the final product upon reconstitution; alternatively, whole beans
may be independently cooked, flavored, and dried, and then mixed
with dehydrated small pieces of chopped beans produced
separately.
FIGS. 1 and 4 show one embodiment of the apparati which may be used
to practice the invention. As shown in these figures, a stationary
vessel 10 comprises a vessel shell 12, and a central shaft 30.
Although the figures show that the vessel 10 has a substantially
circular cross-section, this is done for purposes of demonstration
only, and it is intended that the invention encompass other vessel
configurations as well.
The vessel 10 is also equipped with a solid-blade baffle 20, which
is attached to, and rotates around, shaft 30. In the preferred
embodiment, baffle 20 has a length and width that are substantially
as long as the length and width, respectively, of the vessel 10.
Therefore, in the embodiment of FIGS. 1 and 2, the width of the
baffle 20 is substantially commensurate with the diameter of a
cross-section of the vessel 10. To ensure proper operation, a
clearance of less than 3/16 inch is maintained between the inner
surface 18 of the shell 12 and an edge 24 of the baffle 20, as well
as between an end 28 of the baffle 20 and an end 11 of the vessel
10.
As is shown in FIG. 2, at any point in time, the baffle 20 divides
the inner space of the vessel 10 into two chambers, 14 and 16,
where each chamber is defined substantially by the space between
the inner surface 18 of the vessel shell 12, and a wall 26 of the
baffle 20. The solid-blade baffle 20 has transverse holes 22 (shown
in FIG. 1, and by dashed lines in FIG. 2) which, while large enough
to allow fluids within the vessel 10 to travel between the chambers
14 and 16, are small enough to keep the vessel contents 100
separated on each side of the baffle 20.
In a preferred embodiment, the vessel 10 is employed both to
hydrate raw beans and to cook the hydrated beans. As will be
explained in detail below, when used in the latter capacity, the
vessel 10 is transformed into a pressure cooker, using steam to
cook the beans. To achieve uniform steam injection into the
chambers 14 and 16, steam is forced through the shaft 30, and
enters each chamber 14, 16 through steam outlets 32 which are
arranged along the length of the shaft 30 (FIG. 3). However, steam
can also be injected into the vessel through other suitably placed
entrances to the vessel.
FIG. 4 depicts the remaining components of an embodiment of the
invention. Channel 40 is an elongated hollow structure which is
equipped with a rotating blade 50 and a perforated plate 60
adjacent its distal end 42. The proximal end 41 of the channel is
located adjacent the vessel 10 and receives the cooked beans from
the vessel 10. Once received, the beans are urged through the
channel by a piston or other suitable mechanism, such as a rotating
shaft with advancing flights. Therefore, as the blade 50 rotates,
it chops cooked beans into pieces, which are then urged through the
holes 62 of perforated plate 60 (FIG. 5). It is noted that,
although the plate 60 is shown to have a rectangular cross-section,
the present invention is not intended to be limited to this
configuration; rather, both the plate 60 and the channel 40 may
have cross-sections of various geometries. Moreover, the rotating
blade 50 and perforated plate 60 may be disposed at other locations
along the longitudinal axis of the channel 40.
The channel 40 is adjacent to, and in flow communication with, a
forming conduit 70, which comprises an inlet 72 and an outlet 74.
As is explained in more detail below, chopped beans exit the outlet
74 in a flat sheet of textured composition, where the flat sheet
has a generally rectangular cross-section. The thickness and shape
of the sheet are determined by the conduit outlet 74.
More specifically, FIGS. 9A 9C show various cross-sections of the
sheet of textured material. For example, where the outlet 74 of the
forming conduit 70 has a rectangular cross-section of thickness T
(see FIG. 4), a generally flat sheet of textured composition is
produced that also has a generally rectangular cross-section, with
thickness T.sub.1 (see FIG. 9A), where the magnitude of T.sub.1 may
be slightly less than the magnitude of T. On the other hand, the
outlet 74 may have ridges, or ribs, on its top and/or bottom
surface(s). As shown in FIGS. 9B and 9C, this will result in a
sheet of texturized composition that also has ridges (or ribs) 99
running longitudinally on its top and/or bottom surface(s).
It is noted that the cross-sectional configuration of the sheet of
texturized composition is generally determined by striking a
balance between throughput and drying efficiency. That is, on the
one hand, the thicker the sheet of texturized composition, the
higher the amount of beans that can be processed for a given speed
through the forming conduit 70. On the other hand, the thicker the
sheet of texturized composition, the higher the required amount of
time for exposure to heat (or other drying mechanism) which, in
turn, translates into a slower processing speed--or, put another
way, if the speed is kept constant, then a thicker sheet of
composition may not be sufficiently dried. In this regard,
experimental results indicate that, in a preferred embodiment, all
sections of the sheet are typically less than about 1/4 inch
thick.
FIG. 6 shows, in condensed flow-chart format, an embodiment of a
method of the invention. In practice, raw whole beans are cleaned,
washed, and placed into chambers 14 and 16 of stationary vessel 10,
on either side of the baffle 20. Water is then added to the vessel
10 in an amount that is at least equal in weight to the weight of
the beans in the vessel. Although, in principle, the beans could be
hydrated by just allowing them to soak in the water for a period of
time, experience has shown that this practice results in
non-uniform water absorption by the beans. That is, over time, as
the beans on the top of the pile absorb water, the water level in
the vessel decreases, which causes non-uniform water absorption
throughout the pile of beans.
On the other hand, it is known that raw beans typically have an
initial moisture content in the range 6% 14%. However, given their
non-uniform hydration procedures, prior-art methods cannot use a
batch of raw materials that includes beans and legumes from this
entire range because the disparity in initial moisture levels may
exacerbate the variations in water absorption during hydration, so
that the result would be a highly non-uniform final product. As
such, for every batch of raw materials, the prior art is limited to
using raw beans that fall within a small range of initial moisture
content, e.g., 6 8%, or 12 14%. The present invention, however, is
not so limited.
In a preferred embodiment, once water has been added to the raw
beans in the vessel 10, the baffle 20 is activated, and the beans
are hydrated at atmospheric pressure and a temperature between
150.degree. F. and 200.degree. F. By rotating around the central
shaft 30, the baffle 20 continuously brings the beans into contact
with water, so that the beans do not generally remain in one place
throughout the hydration step. That is, the beans are continuously
replaced from the top to the bottom, and vice versa. In addition,
the holes 22 of the baffle 20 ensure that water is exchanged
between the chambers 14 and 16, so that the hydrating water is not
stationary either, and reaches the beans in both chambers. The
combination of the rotating baffle 20 and the water exchange
between the chambers 14 and 16 allows the moisture level in all of
the beans to equilibrate to about the same level. Typically, during
the hydration step, the beans absorb between 50% and 80% of the
water that they are capable of absorbing.
In a preferred embodiment, the legumes are cooked using direct
steam injection. Therefore, there is no need to have any water in
the vessel 10 while the beans are being cooked. Thus, once the
beans have been properly hydrated, any excess water can be removed
from the vessel 10. There is, however, an added advantage to
removing excess water, namely, that flatulent sugars are also
removed along with the excess water, which results in improved
digestibility of the final bean product.
An option, at this point, is to add salt or other flavoring,
colorant, or oil to a portion of the removed water, and then return
the combination to the vessel 10. In cases where this is done, a
relatively small amount of water is added back to the vessel 10, so
that it is generally insufficient to cover all of the beans in both
chambers 14, 16. Also, either as a substitute for, or a supplement
to, this option, oil, colorant, salt, and/or other flavoring may be
added at various other steps within the process (e.g., after
cooking or during the chopping step).
Using direct steam injection, the vessel 10 is now pressurized
above atmospheric pressure, and the beans are cooked at a
temperature greater than 212.degree. F. Specifically, steam is
injected into the vessel 10 and chambers 14 and 16. During the
cooking step, the baffle 20 rotates around the central shaft 30 as
it did during the hydration step, thus continuously contacting
beans in each chamber 14, 16 with the small amount of water that
rests at the bottom of the stationary cooling vessel. At the end of
the cooking step, there is little or no water left in the vessel,
and the beans are removed and transferred to the channel 40.
Within channel 40, the cooked beans are urged towards the distal
end 42 via the piston/rotating shaft. As the beans are urged
forward, they are chopped by a rotating blade 50, which rotates at
an angular velocity .omega.. The beans are then pushed through the
holes 62 of the perforated plate 60, which is located distal to the
rotating blade 50 and resizes the chopped beans as they travel past
the plate. In this way, a texturized composition is created,
wherein the texture, or chunkiness, of the composition (and of the
final bean product) is determined by the angular velocity (s of the
blade 50 and the hole sizes of the plate 60. Therefore, the present
invention offers the capability of varying-the texture of the final
bean product to a desired consistency by changing the blade angular
velocity .omega., the size of the plate holes 62, or both.
The chopped beans are next fed through the forming conduit 70. As
shown in FIG. 4, in a preferred embodiment, the inlet 72 of the
forming conduit 70 is connected to the distal end 42 of the channel
40. However, this is not required, as long as the conduit 70 and
the channel 40 are in flow communication, so that chopped beans
exiting the channel from its distal end 42 flow into the forming
conduit through its inlet 72. For example, the inlet 72 may
comprise a hopper, or other inlet configuration, that is situated
within close proximity of, but not necessarily connected to, the
channel 40. Regardless, once the chopped beans are in the conduit
70, they are urged towards the conduit outlet 74. The outlet 74 has
a generally rectangular cross-section which, as was described
previously, may have ridges on its top and/or bottom surface(s), a
thickness T, and a width that is considerably larger than T.
Therefore, as the texturized composition exits the conduit outlet
74, it is formed into a generally flat, continuous elongated sheet
of rectangular cross-section that may have ridges 99 on its top
and/or bottom surface(s).
The elongated sheet of texturized composition is next dried (e.g.,
to a final moisture content of about 10%) and then broken up, or
formed, into chunks, where each chunk is approximately 0.25 to 0.50
inch in size. Alternatively, the bean sheet may be first partially
dried, then formed into chunks which are then completely dried.
In either case, chunks of dehydrated bean product are produced that
have rough, uneven, and porous edges. Moreover, each chunk has a
larger surface area containing these rough edges than do bean
products prepared according to prior-art methods. This translates
into pieces with porous edges that take up and absorb water much
more easily and quickly upon rehydration than is available in the
prior art.
As shown in FIG. 7, an alternative embodiment of the method
disclosed herein may include the following steps: After the beans
are cooked in the vessel 10, they are divided into a first
unchopped portion and a second unchopped portion. The first portion
is then taken through the remainder of the process as before, while
the second portion is kept separate. That is, the beans in the
first portion are chopped in the channel 40, and then formed into a
sheet of texturized composition in the forming conduit 70. The
entire sheet is then dried and broken up into chunks. Beans from
the second portion, which remained unchopped, are separately dried
and added to the broken-up chunks (from the first portion).
Alternatively, separate portions of beans, e.g., those destined to
be chopped and those that are maintained whole, may even be
hydrated and cooked using different processing conditions (e.g.,
using different hydration times, different cooking temperatures,
etc. to make the chopped beans more tender than the whole beans),
and then processed and combined as indicated above (see FIG.
8).
Overall, these alternative embodiments allow for added control over
the texture and composition of the final dehydrated bean
product.
Examples set forth below further illustrate various aspects of the
present invention:
EXAMPLE 1
12 liters of hot water were placed in a small (8 inch diameter by
24 inch long) horizontal cylindrical cooking vessel. The water was
then further heated to 185.degree. F. by passing steam through the
shaft of the central baffle, while slowly rotating the baffle so as
to agitate the water.
Approximately 4000 ml of the hot water was drained from the vessel,
and 7 lb. of dry pinto beans were then placed in the vessel--one
half of these beans being distributed along one side of the baffle,
and the remaining half on the other side of the baffle.
The vessel was then maintained at atmospheric pressure, and the
baffle was alternately and continuously slowly rotated for one (1)
minute each in the clockwise and counterclockwise directions. Steam
was added through the baffle shaft to maintain the bean/water
mixture temperature between approximately 180.degree. F. and
190.degree. F. The beans immediately started to absorb the hot
water, and the rotating baffle served to mix and contact the beans
with a continuously diminishing quantity of water. This hydration
step was continued for 20 minutes, after which approximately 6700
ml of broth was drained from the now partially-hydrated beans. 75
grams of salt was then dissolved in 600 ml of the drained broth and
this salt solution was returned to the cooking vessel.
The hatch to the cooking vessel was now secured and the vessel
pressurized with steam and held at a pressure of 10 psig for 40
minutes in order to cook the beans. During this cooking period, the
cooking vessel baffle continued to rotate alternatively and slowly
for one (1) minute each in the clockwise and counterclockwise
directions. In this manner, all the beans were contacted with the
remaining and continuously reducing broth volume.
At the end of the cooking step, the vessel was depressurized and
the cooked beans with very little remaining liquid broth were
discharged into a holding vessel.
These cooked beans were then chopped and texturized by a small
electrically driven meat grinder, which had a front plate with 1/4
inch holes and knife cutters which rotated against the inner side
of the front plate.
The cooked beans were manually fed into the grinder and the
textured bean mass collected as it exited through the grinder front
plate.
The textured bean mass was then placed in a cylindrical vessel, and
was shaped into a sheet approximately 1/8 inch in thickness and 4
inches wide by applying pressure to the vessel so as to force the
bean mass through a 1/8 inch by 4 inch slot situated at the base of
the vessel.
As the textured bean mass exited the slot, it was continuously
deposited on 6-inch by 6-inch perforated metal squares.
These perforated metal squares, supporting the wet bean sheet, were
transferred and placed on a conveyor that passes through a
convective dryer.
The bean sheet was initially dried for 3 minutes and 45 seconds
using 400.degree. F. hot air impinging on the top and bottom of the
bean sheet.
The partially-dried beans were then broken into smaller pieces,
placed on the perforated metal supporting squares, and finally
dried for 4 minutes in the same convective dryer using 350.degree.
F. hot air.
After cooling, these dried, textured beans were stored for rapid
reconstitution with water, and subsequent use in food items.
It will be apparent to a person of ordinary skill in the art that
embodiments of the present invention are not limited in their
design or application to specific embodiments disclosed herein. For
example, injection of steam into the stationary pressure vessel may
be accomplished through ports in the vessel walls. Alternatively,
recirculating water, rather than directly-injected steam, may be
used to cook the beans.
Embodiments of the present invention are also directed to a method
of preparing a reconstitutable, dehydrated whole bean product in
such a way as to preserve the structural integrity of the whole
beans which, in turn, would significantly enhance the texture and
quality of the bean product. As has been set forth above, such a
method must address, and significantly decrease, the amount of bird
mouthing that is prevalent in methods currently existing in the
art, without adversely affecting productivity levels (i.e.,
throughput).
In one embodiment, the above-mentioned goals are achieved by a
method of preparing dehydrated whole beans so as to preserve the
beans' structural integrity, wherein the method comprises:
cleaning, washing, and cooking raw beans; and drying the cooked
beans in a combination microwave-convection heating process,
wherein the beans are dried by exposure to both microwave energy
and convective heating energy.
The above-mentioned goals are also achieved by a method of
preparing dehydrated whole beans so as to preserve the structural
integrity of substantially all of the beans (i.e., less than about
25% by weight incidence of bird mouthing in the dehydrated
product), wherein the method comprises: providing a heating chamber
for drying of cooked beans, wherein said chamber includes means for
continuously advancing the cooked beans through said chamber; and
drying the cooked beans in said chamber by exposing said beans to
both microwave energy and convective heating energy.
In yet another embodiment, the above-mentioned goals are achieved
by a method of preparing dehydrated whole beans so as to preserve
the beans' structural integrity, wherein the method comprises:
cleaning, washing, and cooking raw beans; arranging the cooked
beans into multiple bean layers; and drying said layers of cooked
beans using microwave energy, convective heating, or both microwave
energy and convective heating energy.
In an alternative embodiment, a method of preparing dehydrated
whole beans so as to preserve the structural integrity of
substantially all of the beans comprises: providing a heating
chamber for drying of cooked beans, wherein said chamber includes
means for continuously advancing the cooked beans through said
chamber; arranging the cooked beans into multiple bean layers; and
drying said layers of cooked beans in said chamber using either
microwave energy, convective heating, or both microwave energy and
convective heating energy.
Embodiments of the invention are also directed to a method for
producing a reconstitutable dehydrated chunky bean product,
comprising: hydrating raw beans; cooking the hydrated beans;
dividing the cooked beans into a first unchopped portion and a
second unchopped portion; chopping said first portion of the cooked
beans to form a composition of a desired texture; forming the
texturized composition into a generally flat sheet; drying the flat
sheet of texturized composition; forming the sheet into chunks;
drying the second unchopped portion using a combination
microwave-convection heating process; and adding the dried second
unchopped portion of beans to said chunks.
In the above process, rather than dividing the cooked beans to
obtain two separate unchopped portions from a single batch of
cooked beans, a first unchopped portion of cooked beans may be
obtained from the latter, and a second unchopped portion may be
obtained from separately-hydrated and/or separately-cooked beans
(e.g., cooked beans prepared under a different set of conditions
than those used to prepare the first cooked, unchopped portion). It
is noted that the designations "first" and "second" are used for
identification purposes only and do not necessarily indicate an
order of carrying out the invention. In addition, in alternative
embodiments, each of the drying steps may by accomplished by using
convective heating, microwave energy, or a combination thereof.
In an alternative embodiment, a method for producing a
reconstitutable dehydrated chunky bean product comprises: hydrating
raw beans; cooking the hydrated beans; dividing the cooked beans
into a first unchopped portion and a second unchopped portion;
chopping said first portion of the cooked beans to form a
composition of a desired texture; forming the texturized
composition into a generally flat sheet; drying the flat sheet of
texturized composition; forming the sheet into chunks; arranging
the second unchopped portion of cooked beans into multiple bean
layers; drying said layers of cooked beans using microwave energy
or a combination of microwave and convective energy; and adding the
dried second unchopped portion of beans to said chunks.
Once again, in the above process, rather than dividing the cooked
beans to obtain two separate unchopped portions from a single batch
of cooked beans, a first unchopped portion of cooked beans may be
obtained from the latter, and a second unchopped portion may be
obtained from separately-hydrated and/or separately-cooked beans
(e.g., cooked beans prepared under a different set of conditions
than those used to prepare the first cooked, unchopped portion). It
is noted that the designations "first" and "second" are used for
identification purposes only and do not necessarily indicate an
order of carrying out the above embodiment of the invention. In
addition, in alternative embodiments, each of the drying steps may
by accomplished by using convective heating, microwave energy, or a
combination thereof.
Thus, embodiments of the present invention utilize convective
heating and/or microwave energy to efficiently dry cooked whole
beans and minimize "bird mouthing". As indicated by data collected
from experiments, in a "dual-mode" drying process, use of the
microwave mode will heat water from inside each bean, thus
minimizing case hardening, and use of the convective mode will
"blow" away evaporated water.
Experiments conducted in connection with the present invention may
be summarized by the following examples. It is noted that, in all
experiments, cooked beans having a moisture level of either about
70% by weight (see Examples 2 16) or about 58% by weight (see
Examples 17 21) were used as starting material. For the latter, raw
whole beans were cleaned, washed, and then cooked using the
apparatus depicted in FIGS. 1 3 herein.
A batch convection/microwave oven was used in Examples 2 21. When
operating in the convection/microwave mode, the oven is set up to
provide intermittent microwave power (of approximately 0.6
kilowatts for approximately 40% of the time). The convection
system, on the other hand, circulates hot air at a defined
temperature, and is on "continuously", in the sense that, when the
microwave mode is "off" (and the convection mode in "on"), energy
is supplied to the heating elements of the convection oven, and
fans (or blowers) blow the hot air through and around the mass of
beans inside the chamber. However, when the microwave mode in "on",
energy is no longer supplied to the heating elements, but the fans
continue to operate, so that hot air inside the chamber is still
forced through (and around) the mass of beans. Thus, during
dehydration, convective heating is supplied in such a way as to
generate and circulate hot air when microwave heating is not
applied, and to circulate existing hot air, without generation of
further convective heat, when microwave heating is applied.
When the convection/microwave oven is operated solely in the
convection mode, the hot air at a defined temperature is simply
recirculated around and through the product, and no microwave
energy is applied.
EXAMPLE 2
A square microwave dish (6 in. on each side, and 11/2 in. deep) was
used to place about 244 grams of cooked whole beans inside a
combination microwave-convection heating oven. With this setup, the
beans arranged themselves in about 2 21/2 layers within the
dish.
The cooked beans had a moisture level of about 70%. The beans were
first exposed to full microwave energy for a period of 31/2 minutes
(to heat them from room temperature to 212.degree. F.). Next, the
beans were dried using both microwave and convective energy for a
period of approximately 12 minutes with the convective air
temperature set at 250.degree. F. During this time interval,
microwave heating was supplied intermittently, for a total of
approximately 40% of the time. In addition, the convection mode was
fully "on" when the microwave mode was "off", and only partially
"on" (i.e., fans continued to operate, so that hot air inside the
oven was forced through and around the mass of beans) when the
microwave mode was "on". At the end of this 12-minute time
interval, the cooked whole bean material remaining in the dish
weighed about 120 grams.
At this time, the beans were mixed, and then dried again in the
oven for an additional period of about 8 minutes. This latter
drying process was also carried out with the same combination
microwave-convective heating procedure (with air temperature set at
250.degree. F.) as that which was performed for the above-described
12-minute time period. At the end of the 8-minute time period, a
total weight of about 82 grams of dried whole bean material
remained. This included about 6 grams, or about 7.3%, of dried
beans that were visually identified as being "bird mouthed".
EXAMPLE 3
The experiment of Example 2 was repeated, with the difference that
the drying process was carried out using convective air set at
350.degree. F., rather than at 250.degree. F. Starting with 236
grams of cooked beans, the beans were first heated solely with
microwave energy for 31/2 minutes, and then for successive
12-minute and 8-minute periods using both microwave and convective
heating as described in Example 2. This resulted in 76 grams of
dried whole bean material, of which 14 grams, or about 18.4%, were
identified as being bird mouthed.
EXAMPLE 4
The experiment of Example 2 was repeated, with the difference that
only about one-half as much starting material was used, such that
the beans arranged themselves in a single layer. This resulted in a
shorter heating time, as well as about double the amount of
microwave energy per unit mass of beans. Using the same dish as in
Example 2, this resulted in only one layer of beans.
Thus, about 112 grams of beans were exposed to microwave energy for
about 31/2 minutes. This was then followed by an 11-minute period
of both microwave and convective heating using air set at
250.degree. F. The 41 grams of bean material remaining at the end
of this period contained about 11 grams, or about 27%, of dried
beans identified as being bird mouthed.
EXAMPLE 5
The experiment of Example 2 was repeated, with the difference that
only microwave energy was used to dry the beans. Thus, 254 grams of
cooked beans were exposed to full microwave power for 31/2 minutes,
followed by a 12-minute exposure to microwave energy with the power
set at 40%. The beans were then mixed and dried for an additional
12 minutes using only microwave energy with the power similarly set
at 40%. The 84 grams of dried bean material remaining at the end of
this period contained about 13 grams, or about 15.5%, of
visually-identified bird-mouthed beans.
EXAMPLE 6
100 grams of cooked beans were placed on a perforated rotating
plate and exposed only to convection air heating set at 350.degree.
F. for successive 15-minute and 20-minute time periods. No
microwave energy was applied. Thirty five minutes were needed to
dry the beans. At the end of 35 minutes, all 39 grams (i.e., 100%)
of the dried beans were bird-mouthed.
The following observations may be made based on the results of the
experiments summarized in Examples 2 6 above. First, when
convection is used exclusively to dry the high initial-moisture
(about 70%) beans, the incidence of bird mouthing is higher than
when either microwave energy, or a combination of convective
heating and microwave energy are used. Thus, the pure convection
experiment of Example 6 resulted in almost 100% bird mouthing,
whereas the experiments of Examples 2, 3, and 5 resulted in only
about 7.3% 18.4% bird mouthing. In addition, dehydration using
microwave and convection heating requires less time than when pure
convection is used.
Second, as evidenced by the results of Examples 2 and 3,
dehydration of the beans using a combination of convection heating
(with the air set at 250.degree. F.) and microwave energy results
in much less bird mouthing than when the same process is carried
out at 350.degree. F. As such, it is more advantageous to use lower
initial temperatures in the "dual mode" process in order to avoid
over-heating the beans.
Third, even when the "dual mode" process is carried out at
250.degree. F., increasing the amount of microwave energy to which
the beans are exposed results in a much larger bird-mouthing
percentage due to overheating of the beans. This can be seen by a
comparison of the results of Examples 2 and 4.
The following experiments were conducted in order to explore the
significance of the thickness of the bean layer as the beans are
being dried, as well as to compare the use of pure microwave
energy, as opposed to a combination of convection heating and
microwave energy, to dry the beans.
EXAMPLE 7
Similar to the experiment of Example 5, only microwave energy was
used to dry 224 grams of cooked beans in an "open" dish (i.e., 6
in. on each side, and having no walls). With this configuration,
the beans arranged themselves into approximately 1 2 layers. -After
the initial 31/2-minute (full microwave power) period, the beans
were dried for 12 minutes, then mixed and dried for an additional 8
minutes with the microwave power set at 40%. Of the 72 grams of
bean material remaining at the end of this period, about 23 grams,
or about 32%, of the dried beans were bird-mouthed.
EXAMPLE 8
The experiment of Example 7 was repeated, except that a large bowl
having a base diameter of 6 inches, a top diameter of 7 inches, and
a depth of 41/2 inches was used, which resulted in 2 21/2 bean
layers. After the 231/2-minute dehydration period, about 32% of the
dried beans were bird-mouthed.
EXAMPLE 9
The experiment of Example 8 was repeated (i.e., deep bowl 2 21/2
bean layers), except that a combination of both microwave energy
and convection heating with the air temperature set at 250.degree.
F. was used to dry the beans. After 231/2 minutes (31/2+12+8
minutes), the dried beans exhibited a bird-mouthed rate of about
25%.
EXAMPLE 10
The experiment of Example 7 was repeated (i.e., open dish, 1 2
layers), except that the beans were dried using a combination of
convection heating (with the air set at 250.degree. F.) and
microwave energy. With the beans again arranging themselves in
about 1 2 layers, after 231/2 minutes (31/2+12+8 minutes) and
drying at about 250.degree. F., the dried beans exhibited a
bird-mouthed rate of about 33%.
EXAMPLE 11
Beans were placed in a small bowl (about 41/2 inches in diameter
and 31/2 inches deep), where they arranged themselves in 4 5
layers. The beans were dried using a combination of both convection
heating (with the air set at 250.degree. F.) and microwave energy.
After 231/2 minutes (31/2+12+8 minutes), the dried beans exhibited
a bird-mouthed rate of about 11%. This experiment was repeated a
second time, with a bird-mouthed rate of about 8%.
EXAMPLE 12
The experiment of example 11 was repeated, except that only
microwave energy (at 40% power level) was applied. After 231/2
minutes (31/2+12+8 minutes), the dried beans exhibited a
bird-mouthed rate of about 10%.
EXAMPLE 13
In order to assess the impact of drying under high humidity
conditions, a large container having a diameter of 81/2 inches, a
depth of 11/2 inches, and a lid having 8 transverse 1/8-inch holes
was used to dry beans with microwave energy only. Beans were placed
in the container and the lid used to cover the container. The
beans, which arranged themselves in only 1 layer, were first dried
for 31/2 minutes at full power, followed by a 12-minute period with
the microwave at about 40%. The beans were then mixed and dried for
an additional 11 minutes using the microwave at about 40%. The
dried beans exhibited about 14% bird mouthing.
EXAMPLE 14
The experiment of Example 13 was repeated with the lid removed. At
the end of 261/2 minutes, the dried beans exhibited about 30% bird
mouthing.
EXAMPLE 15
A flat bowl (6 inches on each side, and 11/4 inches deep) was used
to place about 230 grams of cooked whole beans inside a combination
microwave-convection heating oven. With this setup, the beans
arranged themselves in about 2 21/2 layers within the bowl.
The beans were first exposed to full microwave power for a period
of 31/2 minutes. Next, the beans were dried for a period of
approximately 12 minutes using both microwave energy (with power
set at 40%) and convective heating (with the air temperature set at
250.degree. F.). The beans were then mixed and dried for an
additional 8-minute period. Of the remaining 63 grams of bean
material about 9 grams, or about 14.3%, of the beans exhibited bird
mouthing.
EXAMPLE 16
The experiment of Example 15 was repeated, with the difference that
only microwave energy was used to dry the beans. After 231/2
minutes (31/2+12+8 minutes), the dried beans exhibited a
bird-mouthed rate of about 27%.
The following observations may be made based on the results of the
experiments summarized in Examples 7 16 above. First, when the
beans are arranged in about 1 2 layers, dehydration with pure
microwave energy as opposed to a combination of convective heating
and microwave energy yields similar results. Thus, in Examples 7
and 10, 32% and 33%, respectively, of the beans were
bird-mouthed.
Second, with 4 5 bean layers, dehydration with either pure
microwave energy or a combination of convective heating and
microwave energy yields very attractive results. Thus, Examples 11
and 12 indicate that, with multiple layers, especially in the range
of 4 5 layers, a bird-mouthed rate of 8% 11% may be achieved.
Third, when the beans are arranged in 2 21/2 layers in such a way
that the effect of convection heating is either minimized or
eliminated, dehydration using either pure microwave energy or a
combination of convective heating and microwave energy yields
similarly high bird-mouthed rates. Thus, in Examples 8 and 9, the
relatively deep bowl in which the beans were dried nullifies the
effect of convection heating, such that bird mouthing in the range
of 25% 32% is observed.
Fourth, when the beans are arranged in 2 21/2 layers, and the
effect of convection heating is not minimized or eliminated,
dehydration with a combination of convective heating and microwave
energy yields more advantageous results than dehydration with pure
microwave energy. Thus, the experiment of Example 15 resulted in a
bird-mouth rate (14.3%) that was about half as much as that
achieved in the experiment of Example 16 (i.e., about 27%).
Finally, when the beans are arranged in a single layer, as in
Examples 13 and 14, dehydration of the beans in the presence of a
higher amount of humidity provides better results. Thus, in the
experiment of Example 13, a 14% bird-mouthing rate was achieved,
compared to about 30% in the experiment of Example 14.
For purposes of comparison with the results of the above
experiments, the following experiments were carried out using beans
having a lower initial moisture content of about 58% that were
cooked using the apparatus depicted in FIGS. 1 3 herein:
EXAMPLE 17
A flat dish (6 in. on each side, and having no walls) was used to
place about 188 grams of cooked whole beans inside a combination
microwave-convection heating oven. With this setup, the beans
arranged themselves in about 1 2 layers within the dish.
The beans were first exposed to full microwave energy for a period
of 31/2 minutes. Next, the beans were dried for a period of
approximately 12 minutes using both microwave and convective
heating with the circulating air temperature set at 250.degree. F.
During this time interval, microwave heating was supplied
intermittently, for a total of approximately 40% of the time. In
addition, the convection mode was fully "on" when the microwave
mode was "off", and only partially "on" (i.e., fans continued to
operate, so that hot air inside the oven was forced through and
around the mass of beans) when the microwave mode was "on". At the
end of this 12-minute time interval, the cooked whole bean material
remaining in the dish weighed about 82 grams.
At this time, the beans were mixed, and then heated again in the
oven for an additional period of about 3 minutes. This latter
heating process was also carried out using circulating air
temperature set at 250.degree. F., with the same combination
microwave-convective heating procedure as that which was performed
for the above-described 12-minute time period. At the end of the
3-minute time period, a total weight of about 77 grams of cooked
whole bean material remained. This included about 8 grams, or about
10%, of the dried beans exhibiting a bird mouthed effect.
EXAMPLE 18
The experiment of Example 17 was repeated, with the difference that
the successive 12- and 3-minute drying stages were carried out
using circulating air temperature set at 225.degree. F. rather than
at 250.degree. F. The dried beans exhibited a bird-mouthed rate of
about 9%.
EXAMPLE 19
190 grams of cooked whole beans were placed on a flat dish (6 in.
on each side, and having no walls), such that the beans arranged
themselves in about 1 2 layers within the dish. The beans were
exposed only to microwave energy at full power for an initial
period of 31/2 minutes, followed by 12 minutes of microwave energy
at about 40% power (as explained above). The beans were then dried
for an additional period of 4 minutes, again using solely microwave
energy at about 40% power. At the end of the 191/2-minute process,
the dried beans exhibited a bird-mouthing rate of about 16%.
EXAMPLE 20
188 grams of beans were placed in a large container having a
diameter of 81/2 inches and a depth of 11/2 inches, and the
container was closed with a lid having 8 transverse 1/8-inch holes.
The beans, which arranged themselves in only 1 layer, were dried
using microwave energy only. The beans were first dried for 31/2
minutes at full microwave power, followed by a 12-minute period
with the microwave at about 40%. The beans were then dried for an
additional period of 4 minutes, again using solely microwave energy
at about 40% power. At the end of the 191/2-minute process, the
dried beans exhibited a bird-mouthing rate of about 5%.
EXAMPLE 21
188 grams of beans were placed in a small bowl (about 41/2 inches
in diameter and 31/2 inches depth), where they arranged themselves
in 4 5 layers. Using microwave energy only, as in Examples 19 and
20, the beans were first dried for 31/2 minutes, followed by a
12-minute period with the microwave at about 40%. At the end of the
151/2-minute process, the dried beans exhibited almost no
bird-mouthing at all.
The following observations may be made based on the results of the
experiments summarized in Examples 17 21 above. First, dehydration
of cooked beans having a higher initial moisture content results in
a higher rate of bird mouthing in the dried bean product. Thus, for
instance, the experiments of Examples 7 and 10, in which beans
having an initial moisture content of about 70% were used, yielded
bird-mouthing rates of about 32 33%. In contrast, the experiments
of Examples 17 and 19, in which beans having an initial moisture
content of about 58% were used, yielded bird-mouthing rates of
about 10 16%.
Second, with multiple bean layers, and in particular, with 4 5 bean
layers, bird mouthing of the beans can be essentially eliminated.
See, e.g., Example 21. In addition, as evidenced by the results of
the experiment of Example 21, dehydration of the beans can be
achieved in a shorter amount of time than would be possible with
either pure convection heating or drying with 1 2 bean layers. In
this regard, the experiment of Example 19, for instance, in which
the beans arranged themselves in 1 2 layers, required 191/2 minutes
to dry the beans using microwave energy. In contrast, the
experiment of Example 21 required only about 151/2 minutes to
accomplish the same task.
Third, as shown by a comparison of the results of the experiments
of Examples 19, 20, and 21, the incidence of bird mouthing can also
be reduced by drying the beans in a higher-humidity environment.
Thus, the experiment of Example 20 resulted in only about 5% of the
beans exhibiting bird mouthing, as opposed to about 16% in the
experiment of Example 19. In addition, this reduction in bird
mouthing can be achieved in a shorter amount of time (i.e., in this
case, 191/2 minutes) than would be possible with pure convection
heating. Nevertheless, the higher-humidity dehydration process
summarized in Example 20 is still slower than the larger-bean-layer
dehydration process summarized in Example 21. Thus, it appears
that, although either higher humidity conditions or larger bean
layers may be used to decrease bird-mouthing rates, the dehydration
process is faster when multiple bean layers are used.
Finally, with 1 2 layers of beans, dehydration using a combination
of convective heating and microwave energy appears to be a slightly
faster process than dehydration using pure microwave energy. Thus,
the experiment of Example 17 took about 181/2 minutes to complete
and resulted in a bird-mouthing rate of about 10%. The experiment
of Example 19, on the other hand, took about 191/2 minutes to
complete and resulted in a bird-mouthing rate of about 16%.
In this regard, and for purposes of comparison, beans from both
moisture categories, i.e., those having an initial moisture content
of about 58% (that were cooked using the apparatus depicted in
FIGS. 1 3 herein) and those having an initial moisture content of
about 70% were separately dried in a continuous impingement
convection oven (e.g., Lincoln impingement oven) using convection
only. In both cases, the beans were placed on a teflonized
perforated plate (12 in..times.12 in.), where they arranged
themselves in about 1 11/2 layers. The beans were then dried for
just over 10 minutes at 235.degree. F., followed by 81/2 minutes at
265.degree. F., and 91/4 minutes at 300.degree. F. Thus, the total
drying time was about 28 minutes.
In several experiments carried out according to the above
conditions, at the end of the 28-minute period, the
lower-moisture-content beans exhibited a bird-mouthing rate in the
21% 24% range. In contrast, the beans having a higher moisture
content exhibited almost 100% bird mouthing. Comparison of these
results with those of the above-described Examples indicates that,
while drying the lower-moisture-content beans using solely
convective heating may result in slightly higher drying times, it
does, nevertheless, allow for bird-mouthing rates that are below
25%, i.e., where a substantial fraction of the dried whole beans
preserve their structural integrity.
All in all, the above experiments point to an extremely attractive,
and surprising, result: dehydration of beans in larger layers using
either pure microwave energy or a combination of convective heating
and microwave energy provides not only lower bird-mouthing rates,
but also higher throughput. Thus, embodiments of the present
invention provide for an industrial solution whereby more beans can
be produced in a shorter amount of time, with a substantial
fraction of the beans retaining their structural integrity.
In this regard, embodiments of the invention may employ a heating
chamber allowing continuous product passage therethrough, rather
than a traditional convection/microwave oven. Thus, for example, a
heating chamber capable of providing convective heating and/or
microwave energy may be equipped with a conveyor or other similar
means for continuously advancing the beans through the chamber. In
this configuration, the speed of the conveyor will be determined by
the number of bean layers, the exposure temperature, the required
duration of exposure, the level of humidity within the chamber,
etc.
Embodiments of the present invention are also directed to a method
of producing a reconstitutable dehydrated chunky bean product,
wherein dried whole beans produced by the methods described
immediately above so as to be substantially free of bird-mouthing
effects can be added at various points within the process outlined
in FIG. 6. In this way, a reconstitutable dehydrated bean product
may be produced that has an improved amount of chunkiness and
home-made feel due to the existence of actual, structurally intact,
whole beans in the final, reconstituted product.
FIGS. 7 and 8 show additional non-exhaustive, alternative
embodiments of the invention. Thus, in one embodiment shown in FIG.
7, raw beans are first cleaned, washed, hydrated, and cooked. The
cooked beans are then divided into a first unchopped portion and a
second unchopped portion. The first portion of beans is then
chopped into a texturized composition that is, in turn, formed into
a generally flat, and preferably ribbed, sheet. Next, the sheet of
texturized composition is dried and formed into chunks. As shown in
FIG. 7, the second portion of (unchopped) beans may be arranged
into multiple bean layers and dried using microwave energy,
convective heating, or a combination of microwave and convective
energy; the dried whole beans are then added to the chunks (from
the first portion).
FIG. 8 allows for similar alternatives, except that separate
portions of beans, e.g., those destined to be chopped and those
that are maintained whole, are processed according to separate
processing conditions designed to further enhance the organoleptic
properties of the different bean portions (e.g., using different
hydration times, different cooking temperatures, etc. to make the
dehydrated whole beans more tender upon reconstitution with
water).
It is noted that the dried second portion of unchopped beans may
also be added at various other points in the processes shown in
FIGS. 6 8. In addition, as shown in FIGS. 7 and 8 for illustrative
purposes, flavor ingredients and/or oil may be added to either
portion of beans at various points (e.g., prior to cooking, prior
to chopping, etc.).
It will be apparent to a person of ordinary skill in the art that
embodiments of the present invention are not limited in their
design or application to specific embodiments disclosed herein. For
example, while the steps of embodiments of the methodology lend
themselves to dried legumes, other food-stuffs are also within the
scope of the present invention. For example, the apparatus can be
used to cook foods such as carrots, celery, meats, chicken, fish
and the like without the use of excess amounts of water. Thus, the
present invention is intended to encompass all of the embodiments
disclosed and suggested herein as defined by the claims appended
hereto and any equivalents thereof.
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